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Intermembrane Space

Water is produced as a byproduct of

the electron transport chain.

ATP Synthase uses the proton motive force to

generate ATP from ADP as protons move down the concentration gradient

established by the electron transport chain.

Attribution-Noncommercial 3.0 United States more free study guides at www.Biology101.org Anthony DOnofrio

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The Electron Transport ChainNADH and FADH2 from

glycolysis, pyruvate oxidation and the citric acid cycle are

used as the source of energy to pump protons (hydrogen ions) out of the mitochondrial matrix into the intermembrane space

of the mitochondria.

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Oxygen (O2) is used as the final electron

acceptor. This is why we need to breath oxygen!Mitochondrial

Matrix

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Four proteins complexes and one lipid are involved in electron transport:(I) NADH-Q reductase(II) Succinate dehydrogenase(Q) Ubiquinone(III) Cytochrome c reductase(cc) Cytochrome c(IV) Cytochrome c oxidase

Inner Mitochondrial

Membrane

OuterMitochondrial

Membrane

The electron transport chain uses electrons temporarily stored in NADH and FADH2 to reduce a series of membrane associated protein complexes which use the released energy to pump protons out of the mitochondrial matrix. The energy stored in the concentration gradient created is known as the proton motive force and it is subsequently used to power the conversion of ADP to ATP. This chemiosmotic production of ATP is powered by protons diffusing back down the gradient through ATP Synthase.

Note: In prokaryotic cells, electron transport occurs on the cell membrane.